Bone marrow stromal cells provide the microenvironment necessary for lympho-hematopoiesis in vivo. A number of stromal cell clones have been derived from long term bone marrow culture. This heterogenous population of cells remains relatively undefined with respect to their lineage derivation. The project will focus on tissue specific gene regulation in pre-adipocyte stromal cell clones using a combination of cell and molecular biological approaches. Monoclonal antibodies and subtractive hybridization library screening will be used to identify stromal cell specific or abundant gene products. DNA binding protein and transfection assays will serve to determine the trans and cis acting elements regulating these genes. Further understanding of stromal cell gene regulation, in addition to increasing our knowledge of normal physiology, will have impact on bone marrow transplantation as a therapeutic modality for malignancy and inherited genetic disorders.